Kiln for burning or calcining limestone.



Patented Mar. `26, |90l,

W. SPENCER. KILN FR BURNING DR CALCINING LIMESTONE.

(Application flied Sept. 'L 1900.)

2 Sheets-Sinisi` I.

(No Model.)

g w A 7 A afm Ty: Nonms Pneus co. n oumo. WASHINGTON. u. c.

Patented Mar. 20, |901.

W. SPENCER. KILN FDR BURNING 0R CALCINING LIMESTONE.

(Application filed Sept. 7, 1900.)

(No Model.)

iviTnn STATES PATENT Ortisei WILLIAM SPENCER, 0F LOTHERSDALE, ENGLAND.

KILN FOR BURNING OR CALCINING LIIVIESTONE.

SPECIFICATION forming part of Letters Patent No. 670,820, dated March 26; 1901.

Application iiled September 7, 1900. Serial No. 29,274. (No model.)

To all whom, it may concern:

Be it known that I, VILLIAM SPENCER, of Lothersdale, in the county of York, England, have invented certain new and useful Improvementsin Kilns for Burning or Calcining Limestone or Like Substances, of which the following is a specification.

In connection with kilns for the burning or calcining of limestone or like substances,and especially those in which there are two or more superimposed cavities or chambers with constricted intervening passages and openings for the feeding of fuel at two or lnore heights or levels, I have found it desirable to supply air or other combustion-supporting gases at such elevated parts of the said kilns as will insure the thorough consumption in the upper cavity or chamber of the smoke or gases given od by the burning fuel beneath prior to its escaping at the top, thus greatly enhancing the eectiveness of the fuel and at the same time obviating all possibilities of the nuisances that are produced by dense smoke.

Figure 1 represents a sectional front elevation of a kiln for burning or calcining limestone constructed in accordance with my invention. This form of kiln is incased throughout by sheet metal. Fig. 2 represents a sectional side elevation of parts illustrated by Fig. l. Fig. 3 represents a sectional plan on line X X of parts illustrated by Figs. l and 2. Figs. 1 1 and 5 are sectional front and side elevations of my improved kiln, showing the lower part as formed within a walled or earthen embankment, while the upper part is incased by sheet metal. Fig. 6 represents a sectional plan on line X X of parts illustrated by Figs. 4 and 5.

Similar letters of reference indicate similar parts throughout the several views.

The kilns illustrated by the accompanying drawings are typical of the class of kilns to which my invention is applicable, though it will readily be understood that it may be applied to other kilns of somewhat similar general construction, but having certain details therein of a modified formation.

In the kilns illustrated the limestone or like substance is fed through the iron doors at the opening d into the chamber or cavity a and descends on each side of the bridgepiece cinto the cavity b in order that fuel fed through the opening c in the said bridgepiece c may be deposited in the center of the said limestone or the like, in this manner causing the calcining process to be uniformly carried out. The limestone further descends through the constricted opening e into the chamber f, in the upper part of which other openings g are arranged for the feeding of fuel in order that the calcining process may be completed. The calcined limestone orthe like is withdrawn through the drawholes h in the well-known manner.

To devise means whereby the fuel fed through the opening c and the combustible gases resulting therefrom and also from the fuel fed in at the openings g may be eectively burned or consumed at the most desirable place within the kiln is the especial feature of my present invention.

To attain the object of my said invention,I form within the inner walls A of the kiln 'a series of vertical flues m,which lead from the annular cavity n, somewhat surroundingthe lower part of the ki1n,(and which is common to the whole series of iiues m,) to a position approaching the passage e, and at this place I make them converge into a fewer number of flues 0, which finally lead into the kiln, preferably through the walls of said constricted passage e. Appropriate dampers p are employed for regulating the ilow or passage of the currents of air as may be found necessary, an arrangement of these being illustrated by the several figures. When the chamberf is not built into or surrounded by earth, the openings r, as shown by Fig. 3, are formed to lead from various points in the iiue fa, while when the chamber f is built into or surrounded by earth then the openings r are arranged as shown by Fig. 6. This latter formation of kiln, as will be seen, is such as to enable its production out of Lthe old-fashioned running-kiln u. By thus constructing the series of flues m Within the inner wallsA vof the kiln a large proportion of the surface of said walls A is thereby protected against the fierce heat therein by an ever-changing layer of air, s`o that the deteriorating effects thereon are greatly reduced, while the cur- IOO Vthrough the walls of the kiln, caused by a fracture of such Walls or from any other cause,

and to prevent a like ingress of air when following the construction shown by Figs. 4 and 5 I have the walls in the embankment surrounded by an appropriate thickness of fireproof cement concrete s.

Within the upper sheet-metal chimney or shaft fw I mount a damper t, by which the draft through the kiln may be regulated or almost entirely shut off.

Such being the nature and object of my said invention, what I claim is- 1. A kiln comprising in its construction a plurality of superimposed chambers with a constricted intervening passage, fuel-inlets at the upper part of each chamber, and air ues or passages in the walls of the lower chamber, said lues being adapted to supply air to the material located in or descending through the said constricted passage.A

2. A kiln comprising in its construction a plurality of superimposed chambers with a constricted intervening passage, fuel-inlets at the upper part of each chamber, air lues or passages in the Walls of the lower chamber, said dues being adapted to supply air to the material located in or descending through the said constricted passage, and a plurality of dampers for regulating the currents of air through said fines.

3. A kiln comprising in its construction a plurality of superimposed chambers with a constricted intervening passage, a bridge eX- tending across the upper chamber and having a fuel-passage therethrough, fuel-inlets at the upper part of each chamber, and air Iiues or passages in the Walls of the lower chamber, said flues being adapted to supply air to the material located in or descending through the said constricted passage.

In testimony whereof I have affixed my signature in presence of two Witnesses.

WILLIAM SPENCER. 

